Natriuretic Peptides as a Prognostic Marker for Delirium in Cardiac Surgery-A Pilot Study

Medicina (Kaunas). 2020 May 27;56(6):258. doi: 10.3390/medicina56060258.


Background and Objectives: Delirium is a common and major complication subsequent to cardiac surgery. Despite scientific efforts, there are no parameters which reliably predict postoperative delirium. In delirium pathology, natriuretic peptides (NPs) interfere with the blood-brain barrier and thus promote delirium. Therefore, we aimed to assess whether NPs may predict postoperative delirium and long-term outcomes. Materials and Methods: To evaluate the predictive value of NPs for delirium we retrospectively analyzed data from a prospective, randomized study for serum levels of atrial natriuretic peptide (ANP) and the precursor of C-type natriuretic peptide (NT-proCNP) in patients undergoing coronary artery bypass grafting (CABG) with or without cardiopulmonary bypass (off-pump coronary bypass grafting; OPCAB). Delirium was assessed by a validated chart-based method. Long-term outcomes were assessed 10 years after surgery by a telephone interview. Results: The overall incidence of delirium in the total cohort was 48% regardless of the surgical approach (CABG vs. OPCAB). Serum ANP levels >64.6 pg/mL predicted delirium with a sensitivity (95% confidence interval) of 100% (75.3-100) and specificity of 42.9% (17.7-71.1). Serum NT-proCNP levels >1.7 pg/mL predicted delirium with a sensitivity (95% confidence interval) of 92.3% (64.0-99.8) and specificity of 42.9% (17.7-71.1). Both NPs could not predict postoperative survival or long-term cognitive decline. Conclusions: We found a positive correlation between delirium and preoperative plasma levels of ANP and NT-proCNP. A well-powered and prospective study might identify NPs as biomarkers indicating the risk of delirium and postoperative cognitive decline in patients at risk for postoperative delirium.

Keywords: biomarker; cardiac surgery; delirium; natriuretic peptide; off-pump surgery.

MeSH terms

  • Aged
  • Biomarkers / analysis
  • Biomarkers / blood
  • Cardiac Surgical Procedures / adverse effects*
  • Cardiac Surgical Procedures / methods
  • Cohort Studies
  • Delirium / blood
  • Delirium / diagnosis*
  • Delirium / physiopathology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Natriuretic Peptides / analysis*
  • Natriuretic Peptides / blood
  • Pilot Projects
  • Postoperative Complications / epidemiology
  • Prognosis*
  • Prospective Studies
  • Retrospective Studies


  • Biomarkers
  • Natriuretic Peptides